<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    div {
      width: 100px;
      height: 100px;
      background: #000;
      margin: 100px auto;
      transform: rotate(0deg);
      animation: rotate 1s linear infinite;
    }
    
    @keyframes rotate {
      100% {
        transform: rotate(360deg);
      }
    }
    /* 
      deg表示度数
    
     */
  </style>
</head>
<body>
  <div></div>
</body>
</html>